• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.516-528
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• 2015

In this paper, we propose mobile ad hoc network configuration and its autonomous network construction method for efficiency and scalability of media streaming for mobile smart devices. To provide scalable network configuration for streaming traffic distribution, an IEEE 802.11 infrastructure network and ad hoc networks are hierarchically built. The proposed method autonomously configures a hierarchical streaming network by competition based on performance and states of devices and the wireless network, not depending on any specific nodes. Finally, we conduct performance measurement for the proposed configuration and analyze the experimental result.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.205-214
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• 2001

In this Paper, we present an MP4 file streaming system over IP networks. Using the proposed system a user can access MP4 contents in the servers via H) networks and interact with the contents. The MP4 file format is designed to contain the media information of MPEG-4 and is object-oriented. The presented streaming server system contains GUI, session manager, splitter, SL- packetizer and transmitter. In addition, we knave implemented the client system based on the GUI -2D player, the MPEG-4 reference software. The Presented streaming system is designed use RTF for the media data requiring real-time streaming RTCP for QoS management and TCP for the data such as IOD(Initial Object Descriptor), OD(Object Descriptor) BIFS(Binary Format for Scene), which should be transmitted for the streaming and the data, such as still image and text, which can be entirely transmitted in a packet.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.476-481
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• 2012

Recently, QoS/QoE technology as a part of the HTTP-based adaptive streaming technology has attracted attention. In this paper, we find out HTTP-based adaptive and dynamic streaming technology. It is based on a dynamic adaptive streaming system over HTTP, which is designed and implemented. The system consist of conversion by the bit rate of MPEG2-TS files, division of segment, creation of MPD(Media Presentation Description) and bitrate's player through analysis of MPD File between servers and clients in network environments of dynamic and adaptive. This diverse network environments, continuous and smooth playback of video will be used in various multimedia fields.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.690-696
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• 2004

Advanced Television Systems Committee (ATSC) -A/90, which is a standard for terrestrial data transmission in Korea, defines synchronized data that has a strong timing association with a separate Program Element. It is classified as synchronized streaming data that is carried in packetized elementary stream (PES) packets or a synchronized non-streaming data that shall be carried in digital storage media command and control (DSM-CC) section. In this paper, we study the design and verification of synchronized streaming data processing algorithm based on ATSC -A/90. We designed a parser and a player for the algorithm development. The received PES packet including synchronized streaming data is parsed in the parser. The parsed synchronized streaming data is synchronized and displayed by player. Finally, we ascertained that STB was working properly with MPEG-2 transport stream (TS) containing synchronized streaming data, as the proposed algorithm is implemented on a set-top box.

• Broadcasting and Media Magazine
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• v.5 no.2
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• pp.56-64
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• 2000

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.40-47
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• 2009

Recently, dynamic proxy caching has been proposed on the distributed environment so that media objects by user's requests can be served directly from the proxy without contacting the server. However, it makes caching challenging due to multimedia large sizes, low latency and continuous streaming demands of media objects. To solve the problems caused by streaming demands of media objects, this paper has been proposed the grouping scheme with fuzzy filtering based on partition and mapping. For partition and mapping, this paper divides media block segments into fixed partition reference block(R$_f$P) and variable partition reference block(R$_v$P). For semantic relationship, it makes fuzzy relationship to performs according to the fixed partition temporal synchronization(T$_f$) and variable partition temporal synchronization(T$_v$). Simulation results show that the proposed scheme makes streaming service efficiently with a high average request response time rate and cache hit rate and with a low delayed startup ratio compared with other schemes.

• The KIPS Transactions:PartA
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• v.16A no.5
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• pp.327-338
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• 2009

Recently, with the advance of computing and networking technique, the high speed internet becomes widespread, however, it is still hard job to do streaming the media which requires high network bandwidth over the internet. Previous researches for streaming over the internet mainly proposed techniques that controls the QoS(Quality of Service) of the media in proportion to the network status. Though, this could be the solution for the service provider while the service user who wants constant QoS may not satisfy with variable QoS. In the paper, we propose a network adaptive prefetching technique, PAP, for guarantee of constant QoS. The PAP prefetches frames by increasing the frame transmission rate while the available network bandwidth is high. The PAP uses the prefetched frames to guarantee the QoS while the available network bandwidth is low and increases the playout interval to prevent buffer underflow. The experiment result shows that the proposed PAP could guarantee the constant QoS by prefetching the frames adaptively to the network bandwidth with the characteristic of video stream.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.10
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• pp.990-994
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• 2010

Mobile WiMAX does not guarantee the media qualities because it does not consider the characteristics of video coding techniques. In this paper, PC-MCA(Priority-based Combining adaptive Modulation and Coding with ARQ), a priority based channel-adaptive streaming scheme, is proposed to guarantee media qualities. PC-MCA uses QoS scheduler by scheduling priority of the media and differentially controls modulation and coding schemes according to wireless channel condition and frame priorities. It also guarantees multimedia service quality through video decoding reliability.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.10
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• pp.556-568
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• 2003

This paper presents and analyzes the performance of a weighted-window based cache replacement policy for the efficient media caching in streaming media cache servers. The proposed policy makes, for each cached object, use of the reference count, reference time, amount of media delivered to clients and, in particular, the periodic patterns of user requests. Also, by giving weights to the recently referenced media contents, the replacement policy adequately and swiftly reflects the ever-changing characteristics of users preferences. The simulation studies show that the performance of the proposed policy has improved over the conventional policies such as LRU, LFU and SEG - in terms of hit ratio, byte hit ratio, delayed start and cache input.

• ETRI Journal
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• v.44 no.1
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• pp.62-72
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• 2022

In this study, we propose a multi-GPU-based 8KVR stitching system that operates in real time on both local and cloud machine environments. The proposed system first obtains multiple 4 K video inputs, decodes them, and generates a stitched 8KVR video stream in real time. The generated 8KVR video stream can be downloaded and rendered omnidirectionally in player apps on smartphones, tablets, and head-mounted displays. To speed up processing, we adopt group-of-pictures-based distributed decoding/encoding and buffering with the NV12 format, along with multi-GPU-based parallel processing. Furthermore, we develop several algorithms such as equirectangular projection-based color correction, real-time CG overlay, and object motion-based seam estimation and correction, to improve the stitching quality. From experiments in both local and cloud machine environments, we confirm the feasibility of the proposed 8KVR stitching system with stitching speed of up to 83.7 fps for six-channel and 62.7 fps for eight-channel inputs. In addition, in an 8KVR live streaming test on the 5G MEC/cloud, the proposed system achieves stable performances with 8 K@30 fps in both indoor and outdoor environments, even during motion.